MKS Instruments Inc. Insider Trading

MKSI

Last 12 months

Insiders sold $43.4M and bought nothing on the open market.

41% of the selling was scheduled in advance under 10b5-1 plans. President & CEO John Tseng-Chung Lee sold $7.7M on Feb 20, 16% of their stake, outside a plan. The last open-market buy by an executive or director was in Nov 2023.

Net open-market

−$43.4M

0 buys · 32 sales

Under a 10b5-1 plan

41%

of the value sold

Insiders who bought / sold

0 / 13

executives and directors

Last open-market buy

Nov 2023

Nov 7, 2023

Get an email when MKSI's executives or directors buy, or make a large sale outside a plan.

Trades · last 2 years

Date	Insider	Trade	Shares	Price	Value	Of their stake	Filing
Sep 1	Elizabeth Mora Director	Sold10b5-1 plan	300	$250.96	75K	1.6%	Form 4
Aug 14	John Tseng-Chung Lee President & CEO	Sold10b5-1 plan	10,000	$302.01	$3.02M	6.9%	Form 4
Aug 3	John Edward Williams EVP & Gm, Psd	Sold10b5-1 plan	457	$288.31	132K	10%	Form 4
Jun 12	James Alan Schreiner EVP & COO	SoldNo plan 3 parts	3,500	$345.82 average	$1.21M	15%	Form 4
Jun 10	James Alan Schreiner EVP & COO	Sold10b5-1 plan	781	$317.42	248K	3.3%	Form 4
Jun 5	Michelle M McCarthy SVP & Chief Accounting Officer	Sold10b5-1 plan	2,434	$315.23	767K	100%	Form 4
Jun 1	David Philip Henry EVP, Global Str Mktg & GM, MSD	SoldNo plan	6,000	$314.43	$1.89M	37%	Form 4
Jun 1	Elizabeth Mora Director	Sold10b5-1 plan	300	$318.02	95K	1.5%	Form 4
May 27	Joseph B Donahue Director	SoldNo plan	2,100	$327.95	689K	17%	Form 4
May 27	Gerald G Colella Director	Sold10b5-1 plan 7 parts	20,000	$333.40 average	$6.67M	41%	Form 4
May 26	David Philip Henry EVP, Global Str Mktg & GM, MSD	Sold10b5-1 plan	2,500	$330.50	826K	13%	Form 4
May 22	Ramakumar Mayampurath EVP & CFO	Sold10b5-1 plan	8,810	$315.48	$2.78M	100%	Form 4
May 22	John Tseng-Chung Lee President & CEO	Sold10b5-1 plan	10,000	$315.48	$3.15M	6.5%	Form 4
May 18	Peter Cannone III Director	SoldNo plan	1,350	$303.40	410K	15%	Form 4
May 14	Jacqueline F Moloney Director	SoldNo plan	1,000	$312.20	312K	10%	Form 4
May 13	Jacqueline F Moloney Director	SoldNo plan	1,400	$318.99	447K	13%	Form 4
May 11	Eric Robert Taranto EVP & Gm, Vsd	SoldNo plan	2,849	$319.93	911K	18%	Form 4
May 11	Kathleen Flaherty Burke EVP, GC & Secretary	SoldNo plan	4,355	$319.94	$1.39M	8.1%	Form 4
Mar 12	Jacqueline F Moloney Director	SoldNo plan	340	$213.77	73K	3.2%	Form 4
Mar 6	Eric Robert Taranto EVP & Gm, Vsd	SoldNo plan	4,568	$220.52	$1.01M	23%	Form 4
Mar 2	Elizabeth Mora Director	Sold10b5-1 plan	300	$239.44	72K	1.6%	Form 4
Feb 24	James Alan Schreiner EVP & COO	SoldNo plan	4,100	$255.00	$1.05M	15%	Form 4
Feb 20 – 24	Gerald G Colella Director	SoldNo plan 2 parts	20,000	$253.44 average	$5.07M	29%	Form 4
Feb 20	Peter Cannone III Director	SoldNo plan	1,250	$258.06	323K	13%	Form 4
Feb 20	Eric Robert Taranto EVP & Gm, Vsd	SoldNo plan	1,453	$247.55	360K	6.8%	Form 4
Feb 20	David Philip Henry EVP, Global Str Mktg & GM, MSD	SoldNo plan	2,000	$261.56	523K	9.6%	Form 4
Feb 20	Michelle M McCarthy VP & Chief Accounting Officer	SoldNo plan 2 parts	1,466	$250.00 average	367K	100%	Form 4
Feb 20	Jacqueline F Moloney Director	SoldNo plan	829	$247.55	205K	7.2%	Form 4
Feb 20	John Edward Williams EVP & Gm, Psd	SoldNo plan	2,043	$256.41	524K	36%	Form 4
Feb 20	Kathleen Flaherty Burke EVP, GC & Secretary	SoldNo plan	4,254	$250.00	$1.06M	7.3%	Form 4
Feb 20	John Tseng-Chung Lee President & CEO	SoldNo plan 4 parts	30,000	$256.77 average	$7.7M	16%	Form 4
Dec 2, 2025	Elizabeth Mora Director	Sold10b5-1 plan	300	$158.81	48K	1.6%	Form 4
Oct 22, 2025	James Alan Schreiner EVP & COO	Sold10b5-1 plan	711	$138.68	99K	3.1%	Form 4
Oct 1, 2025	Jacqueline F Moloney Director	Sold10b5-1 plan	300	$122.14	37K	2.5%	Form 4
Sep 18, 2025	James Alan Schreiner EVP & COO	Sold10b5-1 plan	838	$124.00	104K	3.5%	Form 4
Sep 18, 2025	David Philip Henry EVP, Global Str Mktg & GM, MSD	Sold10b5-1 plan	5,000	$130.00	650K	24%	Form 4
Sep 2, 2025	Elizabeth Mora Director	Sold10b5-1 plan	300	$99.85	30K	1.5%	Form 4
Aug 1, 2025	Jacqueline F Moloney Director	Sold10b5-1 plan	300	$92.10	28K	2.5%	Form 4
Jul 7, 2025	James Alan Schreiner EVP & COO, Msd	Sold10b5-1 plan	957	$102.44	98K	4.0%	Form 4
Jul 3, 2025	David Philip Henry EVP, Operations & Corp Mktg	Sold10b5-1 plan	2,000	$105.00	210K	8.9%	Form 4

Sep 110b5-1 plan
Elizabeth Mora
Director · sold 300 at $250.96
75K
1.6% of stake
Aug 1410b5-1 plan
John Tseng-Chung Lee
President & CEO · sold 10,000 at $302.01
$3.02M
6.9% of stake
Aug 310b5-1 plan
John Edward Williams
EVP & Gm, Psd · sold 457 at $288.31
132K
10% of stake
Jun 12No plan
James Alan Schreiner
EVP & COO · sold 3,500 at avg $345.82
$1.21M
15% of stake
Jun 1010b5-1 plan
James Alan Schreiner
EVP & COO · sold 781 at $317.42
248K
3.3% of stake
Jun 510b5-1 plan
Michelle M McCarthy
SVP & Chief Accounting Officer · sold 2,434 at $315.23
767K
100% of stake
Jun 1No plan
David Philip Henry
EVP, Global Str Mktg & GM, MSD · sold 6,000 at $314.43
$1.89M
37% of stake
Jun 110b5-1 plan
Elizabeth Mora
Director · sold 300 at $318.02
95K
1.5% of stake
May 27No plan
Joseph B Donahue
Director · sold 2,100 at $327.95
689K
17% of stake
May 2710b5-1 plan
Gerald G Colella
Director · sold 20,000 at avg $333.40
$6.67M
41% of stake
May 2610b5-1 plan
David Philip Henry
EVP, Global Str Mktg & GM, MSD · sold 2,500 at $330.50
826K
13% of stake
May 2210b5-1 plan
Ramakumar Mayampurath
EVP & CFO · sold 8,810 at $315.48
$2.78M
100% of stake
May 2210b5-1 plan
John Tseng-Chung Lee
President & CEO · sold 10,000 at $315.48
$3.15M
6.5% of stake
May 18No plan
Peter Cannone III
Director · sold 1,350 at $303.40
410K
15% of stake
May 14No plan
Jacqueline F Moloney
Director · sold 1,000 at $312.20
312K
10% of stake
May 13No plan
Jacqueline F Moloney
Director · sold 1,400 at $318.99
447K
13% of stake
May 11No plan
Eric Robert Taranto
EVP & Gm, Vsd · sold 2,849 at $319.93
911K
18% of stake
May 11No plan
Kathleen Flaherty Burke
EVP, GC & Secretary · sold 4,355 at $319.94
$1.39M
8.1% of stake
Mar 12No plan
Jacqueline F Moloney
Director · sold 340 at $213.77
73K
3.2% of stake
Mar 6No plan
Eric Robert Taranto
EVP & Gm, Vsd · sold 4,568 at $220.52
$1.01M
23% of stake
Mar 210b5-1 plan
Elizabeth Mora
Director · sold 300 at $239.44
72K
1.6% of stake
Feb 24No plan
James Alan Schreiner
EVP & COO · sold 4,100 at $255.00
$1.05M
15% of stake
Feb 20 – 24No plan
Gerald G Colella
Director · sold 20,000 at avg $253.44
$5.07M
29% of stake
Feb 20No plan
Peter Cannone III
Director · sold 1,250 at $258.06
323K
13% of stake
Feb 20No plan
Eric Robert Taranto
EVP & Gm, Vsd · sold 1,453 at $247.55
360K
6.8% of stake
Feb 20No plan
David Philip Henry
EVP, Global Str Mktg & GM, MSD · sold 2,000 at $261.56
523K
9.6% of stake
Feb 20No plan
Michelle M McCarthy
VP & Chief Accounting Officer · sold 1,466 at avg $250.00
367K
100% of stake
Feb 20No plan
Jacqueline F Moloney
Director · sold 829 at $247.55
205K
7.2% of stake
Feb 20No plan
John Edward Williams
EVP & Gm, Psd · sold 2,043 at $256.41
524K
36% of stake
Feb 20No plan
Kathleen Flaherty Burke
EVP, GC & Secretary · sold 4,254 at $250.00
$1.06M
7.3% of stake
Feb 20No plan
John Tseng-Chung Lee
President & CEO · sold 30,000 at avg $256.77
$7.7M
16% of stake
Dec 2, 202510b5-1 plan
Elizabeth Mora
Director · sold 300 at $158.81
48K
1.6% of stake
Oct 22, 202510b5-1 plan
James Alan Schreiner
EVP & COO · sold 711 at $138.68
99K
3.1% of stake
Oct 1, 202510b5-1 plan
Jacqueline F Moloney
Director · sold 300 at $122.14
37K
2.5% of stake
Sep 18, 202510b5-1 plan
James Alan Schreiner
EVP & COO · sold 838 at $124.00
104K
3.5% of stake
Sep 18, 202510b5-1 plan
David Philip Henry
EVP, Global Str Mktg & GM, MSD · sold 5,000 at $130.00
650K
24% of stake
Sep 2, 202510b5-1 plan
Elizabeth Mora
Director · sold 300 at $99.85
30K
1.5% of stake
Aug 1, 202510b5-1 plan
Jacqueline F Moloney
Director · sold 300 at $92.10
28K
2.5% of stake
Jul 7, 202510b5-1 plan
James Alan Schreiner
EVP & COO, Msd · sold 957 at $102.44
98K
4.0% of stake
Jul 3, 202510b5-1 plan
David Philip Henry
EVP, Operations & Corp Mktg · sold 2,000 at $105.00
210K
8.9% of stake

How to read this. Insiders sell for many reasons: taxes, diversifying, a house. Open-market buys are rarer and say more. A 10b5-1 plan is a trading schedule set up months in advance, so those sales were not timed on news. Large holders (funds and 10% owners) are listed under Everything but not counted as insiders. If you own or watch MKSI, we send a push when an executive buys or makes a large sale outside a plan.

Source: SEC Form 4 filings, filed within two business days of each trade and checked for new ones every hour.

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Held by ETFs

MKSI is in 168 US ETFs. The largest of them, with MKSI's weight in each:

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Download this analysis as a PDF (Pro)

Data sourced from SEC EDGAR filings and third-party price providers. Scores, valuations, and metrics are algorithmic estimates. This is not investment advice. See our Terms and Methodology.

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